Apple Final Cut Pro 5 - Manual (Page 1195)

408 Part II Project Interchange
Example: Using the Image Mask and Mask Feather Filters
In the following example, a still image is used to create an alpha channel in another clip.
1 Apply the Image Mask filter to the clip being keyed, by opening this clip into the
Viewer, then clicking the Filters tab.
2 Drag the Border.tif clip to the clip control of the Image Mask filter.
3 Choose Luminance from the Channel pop-up menu.
Note: When using a clip’s luminance to define transparency, white is used for 100
percent solid, and black is used for 100 percent transparent.
You can further modify this new alpha channel, blurring it with the Mask Feather filter,
for example.
In this example, a grayscale TIF
file, called “Border.tif,” that has a
white center surrounded by a
rough black border, is used.
Drag the clip to the
clip control in this filter.
The clip now has a border that
matches the Border.tif clip.